/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/GroupTopology.h
FGroupEdgeinstances aresharedbetween the two FGroups on either side, viaFGroupBoundary.
struct FGroupEdge
FIndex2i
EndpointCorners
Indexof corners at either end of span, if they exist, otherwise both InvalidID
FIndex2i
Groups
Groups adjoinging this edge, sorted by increasing value if both present, otherwise the second element may be InvalidID (if boundary edge).
FEdgeSpan
Span
Edge span for this edge